Medically Reviewed by Sabrina Felson, MD on May 26, 2020
What is MRSA?
This tiny cluster of bacteria is methicillin-resistant Staphylococcus aureus (MRSA), seen under a microscope. This strain of the common "staph" bacteria causes infections in different parts of the body -- including the skin, lungs, and other areas. MRSA is sometimes called a "superbug" because it doesn’t respond to many antibiotics. Though most MRSA infections are minor, some can be life-threatening.
MRSA Skin Infection: Signs & Symptoms
MRSA infections can appear as a small red bump, pimple, or boil. The area may be tender, swollen, or warm to the touch. Most of these infections are mild, but they can change, becoming deeper and more serious.
MRSA, Spider Bite or Something Else?
Bug bites, rashes, and other skin problems can be confused with MRSA because the symptoms are similar. ER doctors often ask patients who think they have a spider bite whether they saw the spider. These "bites" may turn out to be MRSA. When a skin infection spreads or doesn’t improve after 2-3 days on usual antibiotics, contact your doctor.
MRSA Skin Infection: Cellulitis
MRSA can also lead to cellulitis, an infection of the deeper layers of skin and the tissues beneath them. Cellulitis can spread quickly over a few hours. The skin looks pink or red, like a sunburn, and may be warm, tender, and swollen. The condition usually affects the legs and arms, but not exclusively.
MRSA Skin Infection: Abscess
Skin infections from staph, including MRSA, are prone to forming abscesses. An abscess is a painful lump under the skin that’s filled with pus. Treatment may require surgical drainage and antibiotics.
MRSA: How Do People Catch It?
MRSA is spread by touching an infected person or exposed item when you have an open cut or scrape. It can also be spread by a cough or a sneeze. Poor hygiene -- sharing razors, towels, or athletic gear can also be to blame. Two in 100 people carry the bacteria on their bodies, but usually don't get sick.
Who Gets MRSA?
People who've had recent surgery or a hospital stay are more likely to get MRSA. It's also seen in older people, those living in nursing homes, and people with weakened immune systems. A chronic disease like diabetes, cancer, or HIV raises your chances of coming down with this stubborn infection. And recent antibiotic use is also a risk.
How Safe Are Hospitals?
Hospitals are the main sources of MRSA infections due to the high traffic of ill or wounded patients. They’re working to curb the problem. Efforts include screening patients for MRSA, good hand hygiene, and wearing gloves. It's paying off -- MRSA infections are down an estimated 50% in health care settings.
Can Healthy People Get MRSA?
Yes. Infections are showing up more in people outside of hospitals. These outbreaks -- called community-associated MRSA -- are seen at schools, gyms, day care centers and other places where people share close quarters.
MRSA in Dogs and Cats
It looks like MRSA has jumped from humans to household pets, where it can linger without clear symptoms. Animals can carry the bacteria on their skin and may give it right back to the pet owner or spread it to other animals.
MRSA on the Beach
MRSA has been found in the sand and water at beaches in the U.S. Staph bacteria can live in seawater for several days and reproduce in the sand. A few ways to protect yourself: Cover scrapes before playing in the sand, wash your hands often, shower when you come out of the water, and don’t wear a swimsuit again without washing it.
How Is MRSA Diagnosed?
If you think you have a MRSA skin infection, cover the site with a bandage. Contact a health care provider, who may swab a sample of the area and send it to a lab for testing.
How Is MRSA Treated?
Some infections may only need to be drained, cleaned, and covered at the doctor’s office. Oral antibiotics can treat MRSA, but because it doesn’t respond to many common drugs like methicillin, amoxicillin, penicillin, oxacillin, and cephalorsporins, your doctor may use clindamycin, trimethoprim-sulfamethoxazole, or linezolid. Invasive MRSA can be treated intravenously with Vancomycin.
New Drugs Hit the Market
The FDA is fast-tracking new treatments for MRSA. It has approved three new antibiotics in the past few years: Dalvance (dalbavancin) and Orbactiv (oritavancin), which you get through an IV, and Sivextro (tedizolid phosphate), a pill that you take every day.
MRSA Skin Infection: Home Care
If drugs are prescribed, it's important to finish all doses -- even if your symptoms fade. Stopping early can cause the infection to come back or allow the MRSA bacteria to become immune to the drugs that still work. Keep the sore covered until it has healed and change the bandages when your doctor's tells you to. You should also wash any used bedding, towels, and clothes.
MRSA can spread from a small, contained infection to one that involves your internal organs and body systems. It has been linked to pneumonia and bloodstream infections like sepsis. Current estimates for the United States place the number of severe MRSA infections as high as 90,000 with approximately 20,000 deaths per year.
How to Avoid MRSA
Frequent hand washing with soap and water and using an alcohol-based hand sanitizer are great ways to avoid MRSA. Wipe down surfaces you come into contact with at the gym and shower promptly after any skin-to-skin contact. Don't touch other people's wounds or bandages or share personal items. During a hospital stay, remind staff members to wash their hands before they touch you.
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